C语言 GCC 中宏中函数的无效存储类
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Invalid storage class for a function in a macro in GCC
提问by feos
I have this legacy macro
我有这个遗留宏
#define ASYNC_FUNCTION(x) \
void x(void) { \
static void internal ## x (ASYNCIOCB *); \
ASYNCIOCB *aiocb = AcquireAsyncIOCB(); \
CallAsyncNativeFunction_md(aiocb, internal ## x); \
} \
static void internal ## x (ASYNCIOCB *aiocb)
followed by this one
其次是这个
#define ASYNC_FUNCTION_START(x) ASYNC_FUNCTION(x) {
#define ASYNC_FUNCTION_END ASYNC_resumeThread(); }
And their use looks like this:
它们的用法如下所示：
ASYNC_FUNCTION_START(Occasional_function_name)
{
//actual stuff
}
ASYNC_FUNCTION_END
It compiles fine with cl, but gcc gives
它用 cl 编译得很好，但 gcc 给出
invalid storage class for function ‘internalOccasional_function_name'
static void internal##x (ASYNCIOCB *);
^
I tried to expand them all just to see what it becomes and found nothing broken. I also searched for unclosed curved brackets in the file, and found other macros like this
我试图将它们全部展开只是为了看看它变成了什么，但没有发现任何损坏。我还搜索了文件中未闭合的弧形括号，并找到了其他类似这样的宏
#define Foo_Bar1() { \
extern int foo; \
int bar = foo; \
if (condition) { \
Bar_Foo(); \
} \
#define Foo_Bar2() \
if (condibar != footion1){ \
AbortAsyncIOCB(aiocb); \
return; \
} \
if (condition) { \
Bar_Foo(); \
} \
}
No other headers are included, so other than that last macro looking weird, I couldn't find any obvious errors. I'm using cygwin and I'm fairly clueless.
没有包含其他标题，所以除了最后一个看起来很奇怪的宏之外，我找不到任何明显的错误。我正在使用 cygwin 并且我相当无能为力。
回答by dbush
You can't declare a static function inside of another one. You need to put the declaration outside of void(x):
你不能在另一个内部声明一个静态函数。您需要将声明放在 之外void(x)：
#define ASYNC_FUNCTION(x) \
static void internal ## x (ASYNCIOCB *); \
void x(void) { \
ASYNCIOCB *aiocb = AcquireAsyncIOCB(); \
CallAsyncNativeFunction_md(aiocb, internal ## x); \
} \
static void internal ## x (ASYNCIOCB *aiocb)
Then, if you run the source through just the preprocessor via gcc -E, you'll get something like this (extra spacing added):
然后，如果您只通过预处理器 via 运行源代码gcc -E，您将得到如下结果（添加额外的间距）：
static void internalOccasional_function_name (ASYNCIOCB *);
void Occasional_function_name(void)
{
ASYNCIOCB *aiocb = AcquireAsyncIOCB();
CallAsyncNativeFunction_md(aiocb, internalOccasional_function_name);
}
static void internalOccasional_function_name (ASYNCIOCB *aiocb)
{
{
int a=1;
}
ASYNC_resumeThread();
}
回答by AnT
In C language local function declarations can optionally include storage class specifier extern. That's the only storage class specifier a local function declaration may have. No other storage class specifiers are allowed.
在 C 语言中，局部函数声明可以选择包含存储类说明符extern。这是局部函数声明可能具有的唯一存储类说明符。不允许使用其他存储类说明符。
6.7.1/7:
6.7.1/7：
The declaration of an identifier for a function that has block scope shall have no explicit storage-class specifier other than extern.
具有块作用域的函数的标识符声明除extern 外不应有显式的存储类说明符。
